Tinnitus, the perception of sound in the absence of an external stimulus, is estimated to affect over 1/6 of the American population. The impact of tinnitus on an individual's quality of life can be significant, often negatively influencing vocatinal achievement and emotional and social well-being. Yet despite the high prevalence of tinnitus and its potentially debilitating effects on those who have it, the tools used in modern audiology for tinnitus assessment are wholly inadequate. Diagnosis of tinnitus continues to be based on self-report and descriptions of the tinnitus percept using poorly defined verbal terminology. The studies presented here are intended to fill this critical void with new behavioral tools to diagnos and characterize tinnitus. We will develop, for the first time, an objective behavioral test using adaptations of well-established psychoacoustical methods to identify the presence of tinnitus. We will also improve a patient's ability to describe his tinnitus by applying well-grounded modern methods of cognitive psychology to the evaluation of tinnitus. This approach is innovative because these tools have never been applied to tinnitus assessment. This approach is significant because it will address substantial limitations in tinnitus diagnostics. The outcomes o this project have the potential to form a framework that will guide implementation of these tools in a clinical setting.